California crisis brings attention to Massachusetts dams

Thursday

Feb 16, 2017 at 5:29 PMFeb 17, 2017 at 9:57 AM

Gerry Tuoti Wicked Local Newsbank Editor

While a breach in an emergency spillway on the nation’s largest dam has prompted more than 100,000 northern California residents to flee their homes, Massachusetts officials say they’ve been taking major steps over the past decade to reduce the risk of a catastrophic dam break in the Bay State.

“The Department of Conservation and Recreation’s Office of Dam Safety works closely with key stakeholders, such as state and federal agencies, municipalities and private entities, to protect the public’s safety,” DCR spokesman Troy Wall stated. “The department will continue to make important investments to the agency’s dam infrastructure, monitor dams throughout the Commonwealth of Massachusetts, and assist dam owners to ensure statutory and regulatory obligations are met.”

Over the past decade, the state DCR, which declined to make a dam safety official available for an interview, has invested more than $20 million in dam repairs and improvements.

Of the 10 tallest state-regulated dams in Massachusetts, six were in “satisfactory condition” as of their last inspections, which occurred between November 2014 and November 2016. Two were in “fair” condition,” and two were in “good” condition.

The DCR describes “good” as having no recognized existing or potential deficiencies. Dams in “satisfactory” condition have minor operational and maintenance deficiencies. Dams graded “fair” — such as the Farnham Reservoir Dam in Washington and the Clam Lake Dam in Sandisfield — have significant operational or maintenance deficiencies, but no structural deficiencies.

The most dangerous conditions in the rating system are “poor” and “unsafe,” which are used for structurally deficient dams.

Twelve years ago, the near-failure of an aging timber dam in Taunton spurred the state to re-examine its Office of Dam Safety. During the 2005 crisis in Taunton, the 173-year-old Whittenton Dam threatened to give way after a period of heavy rain. Amid fears a dam burst would send a wall of water cascading through the city, 2,000 residents were evacuated. The Army Corps of Engineers was called to the scene and replaced the old wooden dam with a temporary stone spillway, ending the crisis.

“Taunton was sort of the impetus for everyone to get dams registered and have dams routinely inspected based on the classification of the dam,” said David Gould, director of the Department of Marine and Environmental Affairs for the Town of Plymouth, which is home to 49 dams.

Despite the threat the Taunton dam posed in 2005, it didn’t approach the scale of the Oroville Dam crisis in California, which began when a hole in a spillway was detected Feb. 7. At more than 770 feet, the Oroville dam is the tallest in the country and impounds the second-largest reservoir in California. The tallest dam in Massachusetts, by comparison, is the Cobble Mountain Reservoir Dam in Russell, which measures 245 feet in height.

“There are not too many dams like Oroville,” said Lori Spragens, executive director of the National Association of Dam Safety Officials. “There are only about 40 dams in America that are even close to as big as that dam, and there are about 90,000 dams across the country.”

The size of the Oroville Dam, she said, makes the current crisis in California particularly serious.

There are, however, common issues that affect virtually all dams across the country.

“That dam, the way it’s constructed, is pretty typical, but of course this one is so much bigger,” Spragens said. “But the same amount of maintenance and rehabilitation issues face all dams. There’s deterioration, worries about funding, deferred maintenance, trying to figure out how long you can stretch out the money. Those things face a lot of dams in the United States.”

The National Association of Dam Safety Officials estimates it would cost $60.7 billion to rehabilitate all non-federal dams in the United States, and $18.7 billion just to rehabilitate high-hazard dams.

Managing thousands of dams

There are more than 2,800 dams in Massachusetts, more than half of which are privately owned. Most are left over from long-departed mills, which relied on dams to control the rivers that powered 18th- and 19th-century industrial operations.

“In Massachusetts, there are a lot that are really old, and aging is an issue in every state,” Spragens said. “The biggest risks to dams are aging and deterioration.”

Just 43 Massachusetts dams are used for flood control, and 164 are used to manage water supplies.

“The issues we see are that many of those dams are privately owned, and they go back to when there were mills, and over the years the ownership became murky and the dams in some cases fell into disrepair,” said Abbie Goodman, executive director of the American Council of Engineering Companies of Massachusetts.

In total, 915 Massachusetts dams are owned by cities and towns, 356 are owned by the state and 1,582 are privately owned. Of the privately owned dams, 992 measure less than six feet in height, meaning they are not regulated by the Office of Dam Safety. There are also 289 municipally owned dams and 116 state-owned dams that are not large enough to be the subject of Office of Dam Safety regulation.

The state requires dam owners to register the structures and hire qualified engineers to inspect them. High-hazard dams, the most likely to cause loss of life in the event of a failure, must be inspected every two years. The Office of Dam Safety requires significant-hazard dams to be inspected every five years, and low-hazard dams to be inspected every 10 years.

The hazard potential classification describes what the risk would be in the event of a failure. It is not a reflection of a dam’s condition.

Dams of all hazard levels are located throughout all regions of the state. Large dams and dams located in close proximity to homes are most likely to be classified as high-hazard.

Massachusetts has 333 high-hazard dams, according to the Army Corps of Engineers 2016 national inventory of dams.

Dams that measure less than 6 feet in height or have a storage capacity of less than 15 acres are not required to be inspected.

Major dams owned by the DCR and the Massachusetts Water Resources Authority are inspected monthly. DCR rangers and field staff are also trained to spot major issues with the dams when they conduct daily rounds and visits.

Such sites include the Winsor Dam and Goodnough Dike on the Quabbin Reservoir, the Wachusett Dam and North and South dikes on the Wachusett Reservoir in Clinton, the Sudbury Dam and the Framingham Reservoir. Those dams are all classified as high-hazard.

Repair and removal

Massachusetts got another wake-up call regarding its dams in 2011, when a report from the state auditor identified 100 city- and town-owned dams across the state that were in poor or unsafe condition.

Following that report, state lawmakers in 2013 established a grant program to help fund dam and seawall projects statewide. Using those funds, federal grants and private funds, more than 40 Massachusetts dams have been removed in recent years.

According to a 2015 report from the state Division of Ecological Restoration, it is often less expensive to remove dams than maintain them. Maintenance and repair costs over 30 years, according to the report, are on average 60 percent higher than the cost of removal.

Removing dams that no longer serve a functional purpose not only enhances safety, it also restores rivers to their natural states, improving water quality and supporting the reintroduction of native fish species, dam-removal proponents say.

In Plymouth, four town-owned dams have been demolished in recent years. Next year, the Holmes Dam, the largest remaining municipally owned dam in the town, is expected to come down as well.

Dating back to the 1790s, the Holmes Dam once powered a small tack-and-nail factory.

“If it were to fail, it would likely result in the loss of life and property,” said Gould, the director of the town’s Department of Marine and Environmental Affairs. “It’s located pretty close to downtown Plymouth.”

While Goodman said funding sources such as the state Dam and Seawall Program have helped, more support is needed across the board.

“There’s still a long way to go with high-hazard dams, which, in many cases, are owned by private owners,” she said.